Green Pond Water

Recently used Tetra AquaRem to try to help clear up very green murky water at the suggestion of my local water garden supplier. This helped somewhat, but water is not as clear as I would like. I guess my question to all you veteran water gardeners is how do I keep my water as clear as possible. I add bacteria periodically and have barley bales in my biofalls. My pond is 5,500 gallons. Any help would be welcomed.

Our water garden is 5600 gallons and we have two uv lights. Water goes through first uv light, then pre-filter, then another uv light, and then bio-filters. It's clear all the way to to bottom and it's around 5 feet deep at the center. Good luck and I hope this helps!

I'm significantly smaller than you but in the past 2 years I've used powder bacteria and several different brands and types of "anti-green" chemicals. Everything seems to help each other. But please be careful and check your water often if you have fish. I also have to clean my filters much more often in the spring than I do any other time of the year to keep my water clear.

I totally agree with vic on the UV filter/light. From what I've read for the last 5 years people love them. They do seem a bit pricy but apparently worth it in the long run.

Let us know if you need more help. We'll do what we can. There's a lot of very knowledgable folks on DG that can help.

Sledder is right...the uv lights are a real bite in the wallet. DH thought long and hard before buying the second one. But, the chemicals are not cheap so it's one of those deals where we looked at the overall years etc...Also like Sledder says, filter cleaning is sooooo much more often in the spring during startup. The chemical we used when we did chemicals was accu-clear. It's expensive too but supposedly safe for fish. We never lost any fish using it.

My pond is 5000 gallons. It's going on it's third year. The first two, it wasn't filtered, the water was not clear at all. The only thing I did was add bacteria, it didn't help. We put in a large (8' x 10') veggie filter in last fall. It's rock lined to hold the plants and will be filled with various marginals to aid in filteration. Fired it up about 3 weeks ago and Bingo! Crystal clear water in less than two weeks with just the rocks.

There is finally somewhere for all of that good bacteria to grow. If there's an algea bloom, the plants will take it out in no time.


I'm a firm believer in veggie filters, it fits my style of ponding very well. There are many methods that people use to keep their ponds healthy and clean, some very complex. If it works, then it's good. You just have to find what's best for you.

One problem with using a UV light and bacteria is that the UV can kill the bacteria in the water. So you are defeating your purpose if you have a biological filter and a UV light. If you get the water at the correct balance of bacteria, it will take care of your green water. Also the addition of plants to the pond will help also. Floaters do a miracle with helping to clean the water and to take away the many nitrates that will cause algae blooms.

Thanks to everyone for your wonderful suggestions. I knew I would get great information from experienced pond owners. I'll let you know how I do. Another question??? I live on a lake that has water hyacinths that have survived the winter (I live in zone 7). Is it okay to pluck a few of these out of the lake and put them in my pond? I have checked and the lake maintenance doesn't include any pesticide or other chemical additions.

I'd be EXTREMELY careful taking anything from the "wild". If you really want to try that be sure and wash them off very well and put them into a "holding area" for at least a week.

Tell ya what....the more I think about this idea the less I like it. I just don't trust it. I'd venture to say that if you post that you need floaters someone from DG will help you out.

This message was edited Thursday, May 22nd 11:22 PM

Hi folks. I am new here. Interesting reading, these posts. Just a few observations if I may. I farm and have used barley straw for algea with no success. My pond is in it's third year. Only about 1000 gallons. Water hyacinths (when I can buy them here in Canada) and water lettuce I used for spawning fish. Plus the unkillable hornwort! My pond usually produces hair algea. However, I have found it to be beneficial to the fish. I have an in pond filter that works quite well. Last year I tried raising 'tropical' fish in the pond. (Southern Ontario here.) Quite successfully! I bred Paradise fish and Betta Splendens in the pond. Why? Because I was told it could not be done.

Hi again. Ran out of space. Anyway, will post a pic here of the pond last summer, shallow end. My homepage also has pics of the annual clean out etc,. http://halcanada.tripod.com
I was thinking of trying Koi this year. Not sure about it yet. How many Koi in a 1000 gallon? 4 at 8 inches?